Energy efficiency is a broad term encompassing a range of technologies
that use less energy to provide the same level of energy service as standard or
traditional technologies. An example is a fluorescent light bulb, which
provides the same amount of light as an incandescent bulb, but lasts longer and
consumes less energy. An energy-efficient home may have energy-efficient
appliances (which typically come with an Energy Star label), and may be
weatherized or retrofitted to optimize efficiency.